US4067652A — Method and means for the determination of a plana…

Claim 1

Independent Claim 169 words

Method of determining a planar dimension, for example determining the width of rolled stock, wherein an edge of the surface to be measured is projected on photo-sensitive diodes which are scanned by means of an electronic counter and whereof the individual diode signals are evaluated as a measure of the planar dimension by using the number of counting steps executed between a starter pulse and a brightness break or "jump" as a measure of the dimension to be determined, characterised in that the measuring results of successive individual photo-sensitive diodes are stored in the course of one scanning pass up to the next successive scanning pass and their differences are formed and in that the maximum difference value is stored up to the next scanning of the diode line in order to release a trigger impulse on achieving a greater, or a slightly lower difference value in the course of the following scanning pass of the diode line which trigger pulse terminates the counting steps of the electronic counter.

Claim 2

Dependent Claim 169 words

Method of determining a planar dimension, for example determining the width of rolled stock, wherein an edge of the surface to be measured is projected on photo-sensitive diodes which are scanned by means of an electronic counter and whereof the individual diode signals are evaluated as a measure of the planar dimension by using the number of counting steps executed between a starter pulse and a brightness break or "jump" as a measure of the dimension to be determined, characterised in that the measuring results of successive individual photo-sensitive diodes are stored in the course of one scanning pass up to the next successive scanning pass and their differences are formed and in that the maximum difference value is stored up to the next scanning of the diode line in order to release a trigger impulse on achieving a greater, or a slightly lower difference value in the course of the following scanning pass of the diode line which trigger pulse terminates the counting steps of the electronic counter.

Claim 3

Dependent Claim 52 words

Method according to claim 1, characterised in that the potential pulses of the individual diodes are subjected to a filter circuit which allows only those potential breaks to pass through which correspond to brightness differences in one direction and in that potential variations or "jumps" in the opposite direction are filtered out.

Claim 4

Dependent Claim 26 words

Method according to claim 1, characterised in that the difference between successive pulses is formed by means of a delay circuit consisting of low pass stages.

Claim 5

Dependent Claim 26 words

Method according to claim 1, characterised in that the difference between successive potential pulses is formed by, or with the aid of, an R.C. differentiation unit.

Claim 6

Dependent Claim 36 words

Method according to claim 1, characterised in that in each case the maximum potential difference is stored by means of a peak-rectifier circuit which is discharged by a current source controlled in accordance with scanning frequency.

Claim 7

Dependent Claim 23 words

Method according to claim 1, characterized in that the trigger pulses are released as a result of the peak rectifier circuit being charged.

Claim 8

Dependent Claim 41 words

Method according to claim 1, characterised in that no trigger pulse is released for an inadequately strong maximum potential difference of the diode pulses and instead the counting result of the electronic counter from the previous line scanning pass is retained.

Claim 9

Dependent Claim 43 words

Method according to claim 1, characterised in that it is executed with the aid of a conventional automatically scanning photo-sensitive diode line scanner camera which delivers a single output of a serial time signal indicating the state of illumination of all the diodes.

Claim 10

Dependent Claim 40 words

Method according to claim 8, characterised in that a time variable potential function is pre-applied instead of a time constant potential for the trigger threshold to distinguish between bright and dark diodes, said function being formed by a function generator.

Claim 11

Dependent Claim 22 words

Method according to claim 9, characterised in that the potential function consists of a direct current potential superimposed by a triangular function.

Claim 12

Dependent Claim 152 words

Apparatus for use in determining a planar dimension of an article by detecting the position of an edge thereof, comprising the combination of an array of photo-sensitive semiconductor devices arranged to receive light adjacent said edge, scanning means for cyclically scanning said semiconductor devices, and a counter controlled by said scanning means and arranged to register in each operating cycle the number of signals from the semiconductor devices received between a start signal and a signal produced by the effect of the edge on the light received by the semiconductor devices, characterised by the provision of means for generating difference signals of magnitude determined by the change in the magnitude of the signals produced by successive semiconductor devices scanned and peak storage means for storing the peak difference signal in each cycle, so as to determine the value of the difference signal required in the next succeeding cycle to trigger said counter.

Claim 13

Dependent Claim 152 words

Apparatus for use in determining a planar dimension of an article by detecting the position of an edge thereof, comprising the combination of an array of photo-sensitive semiconductor devices arranged to receive light adjacent said edge, scanning means for cyclically scanning said semiconductor devices, and a counter controlled by said scanning means and arranged to register in each operating cycle the number of signals from the semiconductor devices received between a start signal and a signal produced by the effect of the edge on the light received by the semiconductor devices, characterised by the provision of means for generating difference signals of magnitude determined by the change in the magnitude of the signals produced by successive semiconductor devices scanned and peak storage means for storing the peak difference signal in each cycle, so as to determine the value of the difference signal required in the next succeeding cycle to trigger said counter.

Claim 14

Dependent Claim 23 words

Apparatus as claimed in claim 11 including threshold varying means for cyclically varying the magnitude of the difference signal required trigger the counter.

Claim 15

Dependent Claim 23 words

Apparatus as claimed in claim 11 in which said difference signal generating means includes filter means for removing potential changes in one direction.

Claim 16

Dependent Claim 39 words

Apparatus as claimed in claim 13 in which said filter means comprises a rectifier and capacitor for storing peaks of the waveform from the photo-sensitive semiconductor devices, and a current source for discharging the capacitor at a constant rate.

Claim 17

Dependent Claim 49 words

Apparatus as claimed in claims 11 in which the peak storage means, includes a capacitor, a rectifier connecting one side of the capacitor to the output of the difference signal generating means and a current source connected to said one side of the capacitor for constantly discharging said capacitor.

Claim 18

Dependent Claim 43 words

Apparatus as claimed in claim 15 including a resistor in series with said capacitor and a comparator sensitive to the polarity of the voltage across said resistor, said comparator producing a triggering pulse only when the capacitor is being charged through the rectifier.

Claim 19

Dependent Claim 24 words

Apparatus as claimed in claim 11 in which there are two arrays of said semiconductor device associated respectively with opposite edges of the article.

Claim 20

Dependent Claim 42 words

Apparatus as claimed in claim 17 including means receiving signals from the two edge detecting circuits and from a reference source and producing an output corresponding to the deviation of the measured width from a desired width represented by said reference source.

Claim 21

Dependent Claim 17 words

Apparatus as claimed in claim 11, in which the difference signal generating means comprises a delay circuit.

Claim 22

Dependent Claim 26 words

Apparatus as claimed in claim 19 including a difference amplifier to which the signals at the input and the output of the delay circuit are applied.

Claim 23

Dependent Claim 18 words

Apparatus as claimed in claim 19 in which the delay circuit comprises a series of low pass stages.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1981-01-09	1981-07-11	1982-01-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1985-01-09	1985-07-11	1986-01-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1989-01-09	1989-07-11	1990-01-10	$7700.00	Window Closed / Lapsed

Method and means for the determination of a planar dimension

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